Oscillator for time-pieces



P 26, 6 G. VOSSELER 3,343,365

OSCILLATOR FOR TIME-PIECES Filed March 4, 1965 United States Patent3,343,365 OSCILLATOR FOR TIME-PIECES Gerhard'Vosseler, Basel,Switzerland, assignor to Georges Ceppi, Bassecourt, Switzerland FiledMar. 4, 1965, Ser. No. 437,208 Claims priority, application Switzerland,Mar. 4, 1964, 2,7 64/ 64 4 Claims. (Cl. 58-23) ABSTRACT OF THEDISCLOSURE In an electric time-piece, a bottom plate having mounted onit a battery, a dial train including a ratchet wheel, a resistor and atransistor forming part of a maintenance circuit for an oscillator, theoscillator having at least one collecting member and one driving member,the collecting member being in the input and the driving member being inthe output of the maintenance circuit, the members being in the shape ofa crystal in the form of an elongated blade mechanically coupled whenoscillating at their resonant frequency; a support on the bottom platein one section thereof near the periphery; a pair of parallel grooves inthe support for mounting the members; a rider slidably mounted on theblades for modifying their efiicient length to adjust their oscillationfrequency and a pawl carried by the driving for transmitting itsvibrations to the ratchet wheel.

An oscillator for time-pieces has already been disclosed in a previousUS. Patent No. 3,176,167 filed on Dec. 21, 1962, granted on Mar. 30,1965, to the present applicant for Quartz Oscillator for Time-Pieces.

Said previous application deals with an oscillator for time-piecescomprising at least one collecting member and one driving memberinserted in the input circuit and in the power circuit of an amplifier,respectively, at least one of said members being a crystal the resonancefrequency of which constituttes the time base of the timepiece, said twomembers being mechanically coupled when they oscillate at theirresonance frequency in order to make it possible to have the collectingmember energized by the driving member.

The present invention relates to improvements to oscillators describedin said US. application Ser. No, 246,564, and it is characterized inthat both the collecting member and the driving member are constitutedby a crystal in the shape of an elongated blade, said two blades beingmounted parallel to each other in the plane of the timepiece and beingheld along a small portion of their length by a common support.

The features of the present invention will be disclosed hereafter,reference being had to the accompanying drawing, in which:

FIG. 1 is a general plan view, and

FIGS. 2 and 3 are partial cross-sections along II-H and along IlI-III,respectively, of FIG. 1.

The clockwork movement shown in the drawing comprises a bottom-plate 1on which are mounted a battery 2, a dial-train 3, a resistor 4 and atransistor 5 belonging to the maintenance circuit of the oscillatorwhich is constituted by two crystals 6 and 7 oscillating as explained insaid US. Patent No. 3,176,167. These two crystals have the shape ofblades of rectangular cross-sections mounted in the plane of theclockwork movement parallel to each other and fixed in two grooves madein a support 8 of a non-hygroscopic insulating material. Each of thelateral surfaces of said blades is coated with a metal film 9 which actsas an electrode for the crystals and comes into contact with members 10mounted in support 8, by means of which the two blades are mechanical--ly coupled, and bringing the current from the battery.

ICC.

Said blades are squeezed against said support by a small insulatingplate 11 fixed to the support by means of screws 12 and 11 on both sidesof the two blades. Said small plate 11 prevents the blades from slidingout of their grooves.

A rider 14 mechanically connects the two blades, and its displacementalong the latter permits to modify the eificient length thereof with aview to adjust their oscillation frequency. Said rider is constituted bytwo -T- shaped parts, one of which has a central opening and the other amedian protrusion corresponding to said opening in order that said twoparts can fit together, so .that they squeeze the blades along thesmaller sides thereof.

Blade 6 forms the collecting member of the maintenance electroniccircuit, and blade 7 the driving member thereof. The vibration of thelatter blades are transmitted to the gear-work by a probe 15 fixed bywelding or stuck and by means of a support 16 fixed to the freeextremity of said blade. Said probe carries a plate 17 of ruby servingto cooperate with the teeth of a'ratchet wheel 22 forming the first gearof the gear work of the time-piece. Said ratchet wheel can comprise forinstance 3000 teeth, the spacing between two successive teeth being ofabout 4,14 and the depth 2p. Although not essential, a stopping pawl canbe provided for ensuring a uni-directional rotation of wheel 2.2, saidpawl being mounted on the base 19 comprising a blade 20 and apallet-stone 21.

In the example contemplated, there is also provided an auxiliarystopping pawl which, like driving members 15-17, is constituted by ametal wire 18 fixed to a support 19 by means of a small plate 20 andcarrying a pawl 21 at the extremity thereof. Said auxiliary pawl whichis so directed as to make a given angle with the driving member,prevents the first gear of the gear-work to rotate backwards. It ishowever to be noted that such a stopping pawl is not absolutelynecessary if the angle made by driving member 17 with respect to theperiphery of the driven wheel has been properly chosen.

Such an arrangement has the advantage of being spacesaving and it caneasily be mounted in clockwork movements of any shape, whether round orshaped; in addition, it ensures an excellent acoustic coupling of thetwo crystals.

When the two crystals 6 and 7 are oscillating, probe 15 is caused tooscillate by bending, in view of the weight of the pawl 17 fixed to thefree extremity thereof, said oscillation being similar to that of avibrating string located in the plane of the clockwork movement and pawl17 forming a node of such vibration; in this way, pawl 17 is imparted ato-and-fro movement substantially along the axis of probe 15, thisdisplacement corre sponding to the periodical bending and slackening ofthe probe. The frequency of the bending oscillation of probe 15 is asub-harmonic of the oscillation frequency of the crystal. Theoscillating amplitude of pawl 17 in the longitudinal direction of probe15 is substantially greater than the oscillating amplitude of thecrystals, so that are achieved through probe 15 a reduction of thefrequency, on the one hand, and an amplification of the oscillatingamplitude, on the other hand. If the oscillating amplitude of thecrystal blade is for instance of about 10 mm., the oscillating amplitudeof pawl 17 reaches a few microns, an amplitude which in any case isgreater than the depth of the teeth of the ratchet-wheel, so that it iscertain that pawl 17 will fully disengage from these teeth.

The oscillator according to the invention is characterized by its verysimple geometry, its small size, its safety of operation and also itssmall consumption of current. The electric circuit, being merelyconstituted by a single transistor and two crystals, simply requires acurrent of about a few micro-a-mperes, the result of which 3 is that theoscillating amplitude is independent of the feeding voltage of thebattery. What is claimed is: 1. An electronic time-piece comprising, incombination,

a bottomplate having mounted thereon: a battery, a

dial train including a ratchet wheel, a resistor and a transistorforming part of a maintenance circuit for an oscillator, said oscillatorcomprising at least one collecting member and one driving member, saidcollecting member being in the input and said driving member being inthe output of said circuit, said members each consisting of a crystal inthe form of an elongated blade, said members being mechanically coupledwhen oscillating at their resonant frequency; a support on said plate inone section thereof near the periphery of said plate; said supporthaving a pair of parallel grooves for mounting said members therein; arider slidably mounted on said blades for modifying the efiicient lengththereof to adjust their oscillation frequency; and means carried by saiddriving member for transmitting the vibrations thereof to said ratchetwheel.

2. Electronic time-piece according to claim 1, wherein said supportconsists of a non-hygroscopic insulating material.

3. Electronic time-piece according to claim 1, having stopping means forsaid ratchet wheel, said stopping means comprising a support secured tosaid bottom plate, a wire fixed to said support at one end thereof andcarrying, at the other end thereof a pawl, said pawl being in mesh withsaid ratchet wheel and positioned at an angle with respect to saiddriving member.

4. Electronic time-piece according to claim 1, wherein said members havelateral surface coated with a metal film acting as an electrodetherefor.

References Cited UNITED STATES PATENTS 3,176,167 3/1965 Vosseler 3108.13,192,416 6/1965 Gerber 3108.3 3,192,419 6/1965 Beach 310-83 3,225,22612/1965 Kawakarni 3108.3 3,243 ,95 1 8/ 1962 Kawakami 5823 MILTON O.HIRSHFIELD, Primary Examiner.

I. D. MILLER, Assistant Examiner.

1. AN ELECTRONIC TIME-PIECE COMPRISING, IN COMBINATION, A BOTTOM PLATEHAVING MOUNTED THEREON: A BATTERY, A DIAL TRAIN INCLUDING A RATCHETWHEEL, A RESISTOR AND A TRANSISTOR FORMING PART OF A MAINTENANCE CIRCUITFOR AN OSCILLATOR, SAID OSCILLATOR COMPRISING AT LEAST ONE COLLECINGMEMBER AND ONE DRIVING MEMBER, SAID COLLECTING MEMBER BEING IN THE INPUTAND SAID DRIVING MEMBER BEING IN THE OUTPUT OF SAID CIRCUIT, SAIDMEMBERS EACH CONSISTING OF A CRYSTAL IN THE FORM OF AN ELONGATED BLADE,SAID MEMBERS BEING MECHANICALLY COUPLED WHEN OSCILLATING AT THEIRRESONANT FREQUENCY; A SUPPORT ON SAID PLATE IN ONE SECTION THEREOF NEARTHE PERIPHERY OF SAID PLATE; SAID SUPPORT HAVING A PAIR OF PARALLELGROOVES FOR MOUNTING SAID MEMBERS THEREIN; A RIDER SLIDABLY MOUNTED ONSAID BLADES FOR MODIFYING THE EFFICIENT LENGTH THEREOF TO ADJUST THEIROSCILLATION FREQUENCY; AND MEANS CARRIED THEREOF TO SAID RATCHET WHEEL.